What does the term 'high density altitude' indicate?

The term 'high density altitude' refers to atmospheric conditions where the air density is lower than that at sea level. This is typically experienced at higher elevations or in hotter weather. Thinner air leads to a number of effects, one of the most significant being decreased lift generated by an aircraft's wings or a drone’s rotors. As a result, lift is dependent on air density; when the density is lower, the amount of lift generated for a given speed is also reduced. This is critical information for pilots and drone operators, as they need to adjust their operations for safety and performance under these conditions.

While humidity, atmospheric stability, and turbulence levels can impact flight operations, these factors do not directly define the term 'high density altitude.' Density altitude specifically focuses on air density and its effects on lift capacity, making it crucial for flight safety and performance calculations.